Question

How does pregnancy begin?

Answer 1

Hint: Pregnancy is the state of carrying a developing embryo or fetus inside the female body. positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray are some common ways to confirm pregnancy.

Complete answer:
Pregnancy occurs when the sperm fertilizes the egg, resulting in the formation of the zygote. The zygote is implanted in the uterine wall. The need for nourishment and care arises as soon as the implantation occurs. The zygote grows into an embryo, which then develops into a baby. The placenta, a layer formed between the baby and the mother, assumes this responsibility. The placenta is formed by chorion and the uterine tissue. This layer plays many roles during pregnancy, which are briefly discussed as follows:-

- Supplying nutrients and oxygen to the developing fetus
- It also removes waste materials emitted by the foetus, taking over the functions of the digestive and excretory systems.
- The placenta secretes hormones such as human placental lactogen, progesterone, estrogen, human chorionic gonadotropin, and relaxin, which are required for foetal growth.
- The umbilical cord, which connects the foetus to the placenta, aids in the transportation of nutrients from the mother to the fetus.
- As soon as implantation occurs, the fertilized cell mass or embryo begins to exhibit the triploblastic nature of humans by dividing into three layers of cells. During development, this gives rise to various organs such as ectoderm, mesoderm, and endoderm.

All of these steps following implantation result in the development of the baby, which takes nine months in humans. The progression is slow and steady. The embryo's heart is formed first, followed by limbs, major organs, the appearance of hair, and so on. The fetus is fully developed by the end of 9 months.

Note: It is the process of the uterus contracting at regular intervals to aid in the delivery of the baby at the end of pregnancy. The signals sent by a fully developed fetus through the placenta for ejection are referred to as the foetal ejection reflex. Muscle contractions are caused by these signals. The gestation period is the time from fertilization to childbirth.